<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>User Agent 查看器</title>
</head>
<body>
    <h1>User Agent 结果：</h1>
    <p id="output"></p>

    <script>
        function $(el) {
            return document.getElementById(el);
        }
        const agent = window.navigator.userAgent;
        $('output').textContent = agent;
    </script>
</body>
</html>
